Direct answer: The CK10 manual that HALO links from its CK10 product page says only two settings are needed at start-up: time of day and hardness. Press SET CLOCK to set the time. Press NEXT and the up arrow together to open the installer settings, which run in order through hardness (default 20, range 1–150 grains), day override (1–28 days or off) and regeneration time (default 2:00 a.m.). Press REGEN once to schedule a regeneration tonight, or hold it for three seconds to start one now. The diagnostic screens (up and down together) show gallons used, flow and days since the last regeneration. The manual reserves the OEM set-up menu, which holds capacity and salt dose, for service technicians.
Publisher boundary: Water System Guide is an independent research publisher, not HALO or a HALO dealer. This page summarizes the CK10 operating manual HALO posts on its website (file uploaded November 2024), reviewed October 8, 2026. The manual is a control-valve manual rather than a HALO-branded document, so confirm that the buttons on your valve match its pictures before following it.
Which manual applies to a HALO CK10?
HALO’s CK10 product page links a “CK10 Manual.” That operating manual covers a five-button control valve with NEXT, REGEN, SET CLOCK and up and down arrows. Its warranty page (page 18) is a generic “Residential Water Conditioning Limited Warranty” with a blank “Distributed by” line, and its terms differ from HALO’s own CK10 warranty. See the warranty note below.
Before using any instruction, check that your control has the same five buttons. HALO 5 uses a different controller with SET and arrow buttons; see our HALO 5 installation guide for that one.
How do you set the time on a CK10?
From the manual, page 15:
- Press SET CLOCK.
- Set the hour with the up or down arrow. AM/PM toggles after 12.
- Press NEXT, set the minutes, and press NEXT to exit. REGEN steps back.
The manual says the clock should need setting only after a long power outage, a depleted battery, or a daylight saving time change. A wrong clock moves the regeneration from the middle of the night to a time when the house may be using water. During regeneration, untreated water goes to the house.
How do you set the hardness on a CK10?
Press NEXT and the up arrow together for 3 seconds to open the installer display settings (page 14). The first screen is hardness, in grains per gallon as calcium carbonate: default 20, range 1–150 in 1-grain steps.
The start-up section on page 10 recommends setting hardness 10% above the measured value and adding 2 grains for each ppm of iron. Its example: water measuring 18 grains with 1.5 ppm iron gives 18 × 1.1 = 19.8, plus 1.5 × 2 = 3, for a setting of 23 grains. If your test reports parts per million, the manual’s page 5 says to divide by 17.1 to get grains: 250 ppm is 14.6 grains. Our water hardness calculator does the conversion.
If the hardness screen shows “–nA–”, the valve is not set up as a metered softener. The manual says this happens when FILTER is selected, or AUTO is not selected for gallons capacity, in the OEM menu. Ask the installer.
Day override and regeneration time
Press NEXT from the hardness screen to reach the next installer settings (page 14):
| Screen | What it does | Default or range |
|---|---|---|
| Day override | With gallons capacity set to AUTO or a number, the maximum days between regenerations. With capacity off, the fixed interval. “oFF” means gallons alone decide. | 1–28 days, or oFF |
| Regeneration hour | Hour the regeneration starts | 2:00 a.m. |
| Regeneration minutes | Minutes past the hour | — |
The manual’s setting options table, page 13, explains the combinations. With gallons capacity on AUTO and regeneration timing NORMAL, the valve regenerates at the set time once remaining capacity falls below an automatically estimated reserve, or when the day override is reached. The quick reference panel on page 19 shows a calendar override of 14 as an example value, not a recommendation for your home.
How do you force a regeneration on a CK10?
From page 15:
- Press and release REGEN: “REGEN TODAY” flashes and the valve regenerates at the set time tonight. Press again to cancel.
- Press and hold REGEN for 3 seconds: regeneration starts immediately and cannot be cancelled.
If the brine tank ran out of salt, the manual says to add salt and wait at least two hours before regenerating. On page 5, it says the valve prefills the brine tank two hours before the regeneration time when the prefill option is set. Softened water remains available while the brine is made.
What do the CK10 diagnostic screens show?
Press up and down together for 3 seconds (page 16), then NEXT to step through:
- Days since the last regeneration
- Gallons treated since the last regeneration
- Reserve capacity used, for each of the last 7 days
- Daily gallons treated, for up to 63 days
- Current flow rate in gallons per minute
- Maximum flow rate in the last 7 days
- Total gallons, days and regenerations since the last reset
Gallon and flow screens read zero, or show dashes, if no water meter is installed. To open valve history, press up and down together for 3 seconds, release, then press them together once more (page 17): software version, maximum flow and total gallons since start-up, and an error log of the last 10 errors. If a screen does not appear within 5 seconds, the manual says the valve’s lock is on. It gives the unlock sequence on the same pages.
These screens display values; they do not change settings. The manual still groups them with the technician features (see below), so if you look, photograph the screens for a service call and change nothing. The manual’s diagnostics page also explains how to reset the counters to zero, which is meant for moving the valve to a new location. Do not reset them before a technician has seen them.
Which CK10 settings should owners leave alone?
The manual is explicit. Its advanced programming, diagnostic and valve history features are “intended for use by the service technician or water treatment dealer. Do not attempt to access these features if you are not qualified. Improper settings can cause the unit to malfunction” (page 11).
The OEM softener set-up (NEXT and down for 3 seconds, page 12) holds the settings that size the softener. They include ion-exchange capacity “based on test data,” pounds of salt per regeneration, backwash length, gallons capacity (AUTO, off or a number) and the refill option (post-rinse or prefill). If your softener regenerates too often or too seldom, those values may be the cause. Ask the installer to read them out and record them. Our CK10-150 vs 200 vs 250 comparison explains why capacity and salt dose matter for sizing.
What does “ERROR” mean on a CK10?
If “ERROR” and a number flash alternately, the manual says the valve was not able to function properly and to contact the OEM (page 15). It does not list what each number means. Photograph the display, open valve history to see the error log if you can, and contact the installer or HALO. If the softener is producing hard water without an error, use our HALO not-softening guide.
Salt, iron and the battery note
- Salt: use only nugget, pellet or coarse solar salt with a purity of 99.5% or higher. Do not use rock, block, granulated or ice-cream-making salt, or salt with iron-removing additives. The manual says salt bridges are usually caused by humidity or the wrong salt, and describes breaking one with a broom handle (page 11). The regenerants listed on page 4 include sodium chloride and potassium chloride. Our softener salt guide covers the options.
- Iron: if the water contains iron, the manual recommends cleaning the resin bed at least every six months, or more often if iron appears in the soft water.
- Power loss: the manual contradicts itself. Page 5 says the valve remembers all settings for two hours and then only the time of day needs resetting, and “does not need batteries.” Page 15 says it keeps time for up to 8 hours or until the battery is depleted, and that a non-rechargeable battery should be replaced if the time flashes after a shorter outage. After any outage, check the clock and ask the installer whether your board has a battery.
Frequently asked questions
How do I change the hardness setting on a HALO CK10?
The CK10 manual says to press NEXT and the up arrow together for 3 seconds, then use the arrow buttons to set hardness in grains per gallon. The default is 20 and the range is 1 to 150. Press NEXT to continue through the other installer settings.
What hardness should I set on my CK10?
The manual recommends setting it 10% above your measured hardness and adding 2 grains for each ppm of iron. Its example of 18 grains with 1.5 ppm iron gives a setting of 23 grains. Divide a ppm hardness result by 17.1 to convert it to grains.
How do I make my CK10 regenerate now?
Press and hold REGEN for 3 seconds. The manual says regeneration starts immediately and cannot be cancelled. A single press instead schedules regeneration for the set time tonight.
What does ERROR mean on a CK10 softener?
The manual says a flashing ERROR with a number means the valve could not function properly and to contact the OEM. It does not define each number, so photograph the display and contact your installer or HALO.
Sources and review scope
- CK10 operating manual and programming guide, posted by HALO (file uploaded November 2024); retrieved October 8, 2026. Pages 4–5 and 10–19. The manual carries no HALO revision date.
- HALO CK10 spec sheet, December 5, 2024; retrieved October 8, 2026.
- HALO CK10 softener product page, retrieved October 8, 2026.
- HALO’s own CK10 warranty is covered in our HALO warranty guide.